1. Field of the Invention
The invention relates to a display device, and in more particularly relates to a full color electrochromic display device.
2. Description of the Related Art
Electrochromic materials are expected to replace liquid crystal materials as a mainstream material of display applications moving forward. For display applications, full color technology of the electrochromic materials is a key research area following successful development of rapid voltage switching mechanisms. When an electric field is applied to the electrochromic materials, the electrochromic materials may present different colors due to the shift of the color center absorption peak and may show a high absorption of light rays in a visible spectrum range. When no electric field is applied to the electrochromic materials, the electrochromic materials may present a bleached state and show a low absorption of light rays in a visible spectrum range. Potential applications for the electrochromic materials due to the aforementioned colored or bleached state include applications in smart windows for buildings or cars, in order to prevent rising indoor temperature due to sunlight, or low-end display devices. For display device applications, the electrochromic materials may present colors without conventional backlight modules or color filters. Therefore, the electrochromic materials have advantages of higher contrast ratio and very wide viewing angle, for example, 0 degree to 180 degrees. Additionally, the electrochromic materials have advantages of lower energy consumption due to the lower required applied voltage for driving an electrochromic mechanism of about ±1V. Thus, due in part to the aforementioned advantages, application of the electrochromic materials have the potential to breakthrough some technological bottlenecks in conventional liquid crystal display devices. However, the color gamut for the electrochromic materials is currently not wide enough to comprise the three primary colors (red, blue and green). Therefore, there are still challenges, such as developing an electrochromic display device with full color or flexible substrates capable of full color, before electrochromic display devices may replace conventional liquid crystal display devices.
Therefore, a full color electrochromic display device is needed.